Aerodynamics of long fibres settling in air at 10 < Re < 100

Abstract

The aerodynamics of long aspect ratio nylon fibrous particles has been investigated experimentally whilst settling in air under super dilute conditions without any influence of secondary flows and at fibre Reynolds numbers of 10–100 based on fibre length. Measurement of the orientations and velocities of fibrous particles is undertaken by two-dimensional Particle Tracking Velocimetry (PTV), based on the two end-points. A statistical evaluation of fibres' mean vertical and horizontal components of settling velocities, angular velocity, orientation, number density is presented and used to assess particle aerodynamics.